A planar motion mechanism of a trial measuring analysis system is used for measuring the hydrodynamic coefficients of a submarine body in motion. This mechanism can be applied to test and analyze the hydrodynamic coefficients of a boat mold on the water.
A conventional planar motion mechanism comprises a (two-axis) horizontal planar motion mechanism (HPMM) and a (three-axis) vertical planar motion mechanism (HPMM). In order to actually measure the motion performance of a submarine body in a fluid, it is necessary to consider the compound motion between the axes. Therefore, as shown in FIG. 1, a (five-axis) dual-pillar VPMM is developed. The dual-pillar VPMM comprises two pairs of two axes for a compound motion and an axis to control respective rotations.
However, the design of the conventional dual-pillar VPMM is directed at the hydrodynamic coefficients of a submarine. The compound motion is done by two axes. There is no compound motion in the direction of the X-axis. Therefore, it is unable to imitate the dynamic motion of the submarine. Furthermore, as shown in FIG. 2 and FIG. 3, the dual-pillar VPMM comprises two pillars 10 each disposed on a joint 20 and coaxially connected with a connecting axle 301 of a submarine body 30. When the dual-pillar VPMM is in a pitching or yawing motion, the space L0 between the two joints 20 at a horizontal position is not equal to the space L between the two joints 20 in a pitching or yawing motion. Thus, if the joints are immovable, the dual-pillar VPMM cannot be in motion. Although the joint 20 is provided with a slide sleeve for a pitching or yawing motion, the joint 20 is still subject to the angle. As a result, the angle of pitching and yawing is limited. After yawing, it is hard for the centroid of the submarine 30 to be at the same position as the original position, which will cause a certain deviation. This will increase the variate to measure the hydrodynamic coefficients and the difficulties in measuring and calculating. The error value is raised, so the precision of measuring is lowered. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.